Well after dealing with a stubborn fuel issue (Which turned out to be my fuel tank) I decided to pull out the old Flatty out and drop in my rebuilt 268 Straight Eight and 54 Hydra-matic transmission. The new engine is basically stock, but it is bored .060 over to a 278. Over all the job wasn’t that bad.
I had the old one out in a couple of hours
In with the new, now this was a little bit of a pain. It’s not that the job was tough or anything, but my cherry picker fell over and the engine landed on my toolbox and battery – both destroyed. I pulled the ol’ s10 around and chained the cherry picker to it and finally got the new Flathead in and bolted up.
Besides the engine falling over while trying to put it in, the only other problem I had with this project was getting the drive shaft yoke to slide into the transmission. I like to never got that sucker in there. I actually had to take a board and tap it in with a hammer. I spent overall about 3 hours working with the drive shaft. I spent more time on that drive shaft than I did actually putting the engine in.
After I finally got it in, made sure everything was tight and finally fired the engine up… I put it in gear and NOTHING – transmission is locked up! Turns out the 54 Hydramatic is junk…
So I pulled the 54 transmission back out – had it out in 45 minutes!
I pulled the old transmission off of my old engine and finally got it installed about a week later since I had to order the torus gasket. That transmission is heavy by the way… It was everything I could do to get it slid under the car and raised onto a jack to jack it back up into place. I think I had the transmission back in in about an hour or so. Wasn’t too bad.
In all, I had the engine swap done in about a day, but it took me 9 days to complete the project since I had to order that torus gasket before I could install my old transmission.
I’ve put about 2,000 miles on it since I did the engine swap and so far everything is great. The engine runs smooth and the transmission… well…it shifts haha. 
I have everything to convert it to a straight drive car which I do plan to do, hopefully sometime this winter if I get a chance to.
